Terminal plug



June 24, 1930, W 2H, RAY 1365,54@

TERMINAL PLUG Filed Dec. 1.9, 1925 Patented .lune 24, 1930 lfltdidd T @i r l HARRY RAY, F CHECAGO, ILLINDS, ASSXGNOR 'ZEG WESTERN ELECTRIC Tbl'. Y., A CORQRATUN @F NEW YRE reni/rimer. ienne i Application nled December 19, 1925. Serial. No. /G'l'.

This invention relates to. terminal plugs, and more particularly to a terminal plug for electrical conductors. v-

Electrical conductors such as are used for interconnecting electricalpcircuits are frefluently provided at their free ends with ter minal plugs which are designed to engage jaclr terminals attached to other conductors and which may be iixedly positioned. A plul@ rality of individually insulated conductors of this type assembled under a common sheath to constitute a flexible strand termed a cord is frequently used in telephone exchanges for interconnecting electrical circuits of telel phone switchboards. ln such cases the terminal plug attached to the cord is usually provided with eontacting portions which are insulated from each other, individually connected with the conductors of the cord and gwdesigned to engagey cooperating contacting portions or springs of a jack terminal secured in the telephone switchboard. These contacting portions of the terminal plugs sometimes become Worn from such usage to as such an extent that they are no longer capable of making entirely satisfactory electrical connections with the contacting portions of the l jack terminal. ln order to insure-continuously giving satisfactory service, it has been the practice to frequently'inspect such terminal plugs and discontinue the use of any, the contacting portions of which appear to be nearing the expiration of their service life. ln such instances it has usually been necessary heretofore to` replace the entire terminal plug, although some portions thereof would give entirely satisfactory service for an indefinite period.`

The primary object of this invention is lo to provide an improved terminal plug Wherein the Worn parts may be replaced expeditiously and economically.

ln accordance ,with the invention there is provided in .one embodiment thereof aterminal plug having abody portion bearing a plurality of individually insulated Contact springs which maybe readily and securely attached to the ends of the separate conductors of a multiple conductor cord. A reversiblecontacting member is provided with similarly arranged individually insulated contacting portions at each end which may be used interchangeably for resiliently, rotatably and electrically engaging either the Contact springs of the body portion or the contact springs of a'terminaljaclr.

Other objects and features ofthe invention will become apparent inthe following de! tailed description, reference being had to the accompanying drawing, wherein Fig. 1 is an enlarged elevational view, part'- ly in section, vof a terminal plug embodying the features of the invention;

, Fig. 2 isa longitudinal section-taken on the line 2-2 of Fig. 1 with the, reversible member shown in elevation;

Fig. 3 is an enlarged detailed view of the reversible member; j l

Fig. 4l is a longitudinal section .taken on the line l-Ll of Fig. 3, and

Fig. 5 is an enlarged detailed View of the plug body.

lt is believed that the invention will be clearly understood from a detailed description of a terminal plug embodying the general features thereof.

e Referring now tothe drawing in detail, a

terminal plug embodying/the features of this invention comprises, in general, a body 10 and a reversiblecontacting member 11. rlhe body 10 is tubular in form and is provided on one side with an excision 12 (Fig. 5) to facilitatey the assembling of the plug and its attachment to a liexible triple cnductor cord 14 (Fig. 1). Contact springs 15 and 16 are secured Within the body 10 by means of screws 17 threaded in the wall thereof oppositel the excision 12. rl`he contact springs 15 and i16 vare insulated from each other by means of spacers 18 and 19 of any suitable insulating material, preferably hard rubber. Strips 20 and 21 of insulating material serve to insulate the springs 15 and 16 from the plug body 10 and the screws 17, respectively. The screws are further insulated from the contact springs lby means of insulating bushings 22 (Fig. 2). The ends of conductors 23 and 24: of the cord 1d may be fastened to the contact -springs 15 and 16 by means of screws 25 and 26, respectively. A. third conductor mounting of the member 11 in the plug body (not shown) may be suitably electrically connected to the body 10.

The reversible member 11 comprises a central vmetal member 31 which is of circular cross section and threaded at each end to receive a nut 27 (Fig. 4). Surrounding the member 31 substantially throughout its length is a tube 28 composed of any suitable insulating material, preferably hard rubber. The tube 28 is, in turn, surrounded by a metal sleeve 29 which iselectrically connected at each end to a collar 30 which may be swetted or otherwise secured thereto. Each of the collars 30 is insulated from the member 31 by the tube 28. A metal sleeve 37 surrounds the sleeve 29 and is spaced therefrom by hard rubber bushings 32 which are provided, at opposite ends, with shoulder portions 33 which portions serve to nisulate the sleeve 37 from the collars 30. ADisposed between each of the collars 30 and its associated nut 27 is a collar 35 of enlarged diameter which is insulated on each side by a hard'rubber washer 36 (Fig. ,4) The collars 35 areA also insulated from the member 31 by the ,tube 28.'

The contacting member 11 is designed so that the sleeve 37 thereof fits snugly within the body portion 10 to insure a good electrical connection therewith. Moreover, the contacting member is rotatable in the plug body, thus insuring a uniform wear of its contacting portions. The contact springs 15 and 16' are formed with forked ends which are designed to grip the collar 3() and nut 27 to hold the member 11 securely in place. A shell Zl() composed of fiber or other suitable insulating material iits snugly around the plug body and serves to press the springs 15 and 16 into resilient engagement with the collar 30 and nut 27 respectively.

It is obvious from the above description that the nut portions 27 of the contacting member 11 are electrically interconnected through the central member 31 and the collars 30 are electrically interconnected through the sleeve 29. The nut 27, collar 30, and sleeve 37 serve as the tip, ring and sleeve contacting portions which cooperate with the tip, ring and sleeve contacting springs of a terminal jack in connecting the conductors of the cord 14 with the conductors connected with the terminal jack. Due to the rotatable 10 as hereinbefore described, self-cleaning contacts are produced between the springs 15 and 16 and the ring and tip contacting portions 30 and 27, respectively, as Well asbetween the interior surface of the plug body 10 and the exterior surface of the sleeve 37.

Since either end of the contacting member 11 may be inserted into the plug body, it is obvious that when either the tip or. ring coutacting portion at one end becomes Worn, the contacting member may be reversed to permit the use of the contacting portions at the opso designed that they will make good electrical connections with the tip and ring p0r- 'tions of the member 11 and securely hold the member in the body portion even though such portions are so `worn as to render them unsuitable for electrical engagement with ter-v minal jacks. Furthermore, when the con- .tacting portions at both ends have become worn, the contactingmember 11 maybe replaced by a new one without disconnecting the plug from the conductors.

Although the invention, as herein illustrated and described, is particularly applicable to telephone switchboard plugs, it should be understood that the novel features thereof are capable of other applications and should be limited only by the scope of the appended claims.

Vhat is claimed is: f

1. In a terminal plug for use with a terminal j ack having a plurality of contacting portions, a tubular body having a plurality of individually insulated .contact springs, and a cylindrical contacting member having similarly arranged contacting portions at each end for interchangeably, resiliently and rotatably engaging the contact springs and the contacting portions of the terminal jack.

2. In a terminal plug, a body, contacting means carried thereby, a reversible contact member for engaging the contacting means to form a swivel connection, and means to prevent a. disconnectingl4 of the reversible member from the contact means.

3. In a terminal plug, a reversible connecting means having interchangeable insulated end contacts, a tubular contact having a cutout portion, a plurality of individually insulated contacts secured on one side of the tubular contact opposite the cutout portion, and a member adapted to engage the insulated contacts of the tubular contact through the cutout portion to engage them with the contacts of the reversible connecting means.

4. In a terminal plug, a body, a spring contact carried thereby, a reversible member having a shoulder for engaging the contact, and removable means for forcing the spring Contact over the shoulder to permit of a` swivel connection and to prevent withdrawal of the reversible member. g

` 5V. In a terminal plug, a reversible contact member, an electric contacting support engaging a portion of the reversible member, a spring contact carried thereby, and means for causing an enga-vement ofthe spring con'- tact with the reversible member to permit relative rotation between them and to prevent,

their disengagement.

6. In a terminal 'plug for use with a terminal jack having contacting means, a tubular In Witness whereof, I hereunto subscribe my name this 5th day of December, A. D. 1925.

, IILLIAM'HARIRY RAV 

